Lighting system for growing plants

ABSTRACT

A lighting system includes a first LED array which includes a plurality of LED sub-arrays, and a plurality of inputs operatively coupled to a corresponding LED sub-array through a controller. The intensity of light emitted by the LED sub-arrays is adjustable in response to adjusting input signals provide by the inputs. In this way, the intensity of light emitted by the LED sub-arrays is adjustable, in response to adjusting the input signals, to drive a wavelength spectrum of the first LED array to match the action spectrum of a physiological activity of a plant.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 61/083,499 filed on Jul. 24, 2008, the contents of which are incorporated by reference as though fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to facilitating plant growth using light.

2. Description of the Related Art

Some lighting systems for growing plants utilize gas-based lights and other lighting systems utilize light emitting diodes (LEDs). More information regarding lighting systems for growing plants can be found in U.S. Pat. No. 6,688,759 to Hadjimichael, the contents of which are incorporated herein by reference. Information regarding lighting systems that utilize LEDs can be found in U.S. Pat. No. 5,012,609 to Ignatius et al., U.S. Pat. No. 5,278,432 to Ignatius et al., U.S. Pat. No. 6,474,838 to Fang et al., U.S. Pat. No. 6,602,275 to Sullivan, U.S. Pat. No. 6,921,182 to Anderson et al., U.S. Patent Application Nos. 20040189555 to Capen et al. and 20070058368 to Partee et al. and International Application No. PCT/CA2007/001096 to Tremblay et al., all of which are incorporated by reference as though fully set forth herein.

There are many different manufacturers that use light emitting diodes for the growing of plants. Some of these manufacturers include Homegrown Lights, Inc., which provides the Procyon 100, SuperLED, which provides the LightBlaze 400, Sunshine Systems, which provides the GrowPanel Pro, Theoreme Innovation, Inc., which provides the TI SmartLamp, and HID Hut, Inc., which provides the LED UFO.

However, it is desirable to provide a lighting system which allows the color of the emitted light to be better controlled.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to a lighting system for facilitating the growth of plants. The novel features of the invention are set forth with particularity in the appended claims. The invention will be best understood from the following description when read in conjunction with the accompanying drawings.

These and other features, aspects, and advantages of the present invention will become better understood with reference to the following drawings and description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a block diagram of a lighting system, which includes two inputs operatively coupled to an LED array through an LED controller.

FIG. 1 b is a more detailed block diagram of the lighting system of FIG. 1 a.

FIG. 1 c is a more detailed front view of one embodiment of the LED array of FIG. 1 a, which includes two LED sub-arrays.

FIG. 2 a is a schematic diagram of one input of FIG. 1 a operatively coupled to one of the LED sub-arrays through an LED driver circuit, wherein the input operates as a potentiometer.

FIG. 2 b is a schematic diagram of the other input of FIG. 1 a operatively coupled to another of the LED sub-arrays through another LED driver circuit 141, wherein the other input operates as a potentiometer.

FIG. 3 a is a graph of a wavelength spectrum of light provided by the lighting system of FIG. 1 a.

FIG. 3 b is a graph of another wavelength spectrum of light provided by the lighting system of FIG. 1 a.

FIG. 3 c is a graph of a wavelength spectrum of light provided by the lighting system of FIG. 1 a, wherein the wavelength spectrum includes color mixing.

FIGS. 4 a and 4 b are graphs of wavelength spectra of light provided by the lighting system of FIG. 1 a, and action spectrum corresponding to chlorophyll a and chlorophyll b, respectively.

FIGS. 4 c and 4 d are graphs of wavelength spectra of light provided by the lighting system of FIG. 1 a, and action spectrum corresponding to α-carotene.

FIGS. 4 e and 4 f are graphs of wavelength spectra of light provided by the lighting system of FIG. 1 a, and action spectrum corresponding to β-carotene.

FIG. 4 g is a graph of wavelength spectrum of light provided by the lighting system of FIG. 1 a, and action spectrum corresponding to pelargonin (Perlargonidin-3,5-diglucoside).

FIG. 4 h is a graph of wavelength spectrum of light provided by the lighting system of FIG. 1 a, and action spectrum corresponding to phycocyanin.

FIG. 4 i is a graph of wavelength spectrum of light provided by the lighting system of FIG. 1 a, and action spectrum corresponding to phycoerythrin.

FIGS. 5 a and 5 b are bottom and top perspective views, respectively, of an embodiment of a lighting system.

FIGS. 5 c and 5 d are top and back perspective views of the lighting system of FIGS. 5 a and 5 b.

FIG. 5 e is a front perspective view of the lighting system of FIGS. 5 a and 5 b.

FIG. 5 f is a front view of a first LED array of the lighting system of FIGS. 5 a and 5 b, wherein the first LED array includes five LED sub-arrays carried by an LED array support structure.

FIG. 5 g is a front view of a second LED array of the lighting system of FIGS. 5 a and 5 b, wherein the second LED array includes five LED sub-arrays carried by an LED array support structure.

FIGS. 6 a and 6 b are block diagram of the lighting system of FIGS. 5 a and 5 b, which includes five inputs operatively coupled to the first and second LED arrays through an LED controller, wherein the LED controller includes first and second LED sub-controllers.

FIGS. 7 a, 7 b, 7 c, 7 d and 7 e are schematic diagrams of the inputs of FIGS. 5 a and 5 b operatively coupled to the first LED sub-array through the first LED driver circuit, wherein the inputs operate as potentiometers.

FIGS. 8 a, 8 b, 8 c, 8 d and 8 e are schematic diagrams of the inputs of FIGS. 5 a and 5 b operatively coupled to the second LED sub-array through the second LED driver circuit, wherein the inputs operate as potentiometers.

FIGS. 9 a, 9 b and 9 c are graphs of wavelength spectra of light provided by the lighting system of FIGS. 5 a and 5 b, wherein the wavelength spectrum includes color mixing.

FIG. 9 d is a graph of a wavelength spectrum of light provided by the lighting system of FIGS. 5 a and 5 b, wherein, and the wavelength spectrum of chlorophyll a.

FIG. 9 e is a graph of a wavelength spectrum of light provided by the lighting system of FIGS. 5 a and 5 b, wherein, and the wavelength spectrum of α-carotene.

FIG. 9 f is a graph of a wavelength spectrum of light provided by the lighting system of FIGS. 5 a and 5 b, wherein, and the wavelength spectrum of pelargonin.

FIG. 9 g is a graph of a wavelength spectrum of light provided by the lighting system of FIGS. 5 a and 5 b, wherein, and the wavelength spectrum of sunlight.

FIG. 10 is a block diagram of a lighting system 100 c, which includes a programmable logic controller 133 operatively coupled to LED array 102 through LED controller 130.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 a is a block diagram of a lighting system 100 a, which includes inputs 110 and 111 operatively coupled to an LED array 102 through an LED controller 130. Lighting system 100 a includes a power supply 108 which provides a power signal S_(Power) to LED controller 130 through a power terminal 108 a.

LED array 102 includes two or more different types of LEDs, which are capable of emitting different wavelength spectrums of light. LEDs of the same type emit the same wavelength spectrums of light, and LEDs of different types emit different wavelength spectrum of light. A wavelength spectrum of light is the intensity of light emitted by the LED versus the wavelength of the light, and corresponds to a color of the light. The wavelengths spectrum of light can be determined in many different ways, such as with a spectrometer. Examples of wavelength spectrums of light are discussed in more detail below with the graphs shown in FIGS. 3 a-3 c and FIGS. 4 a-4 i.

It should be noted that the conventions for the wavelengths of different colors of light vary widely. However, the wavelengths of light discussed herein will have the following ranges for ease of discussion:

-   -   Ultraviolet light (UV): 40 nm to 380 nm;     -   Violet light: 380 nm to 450 nm;     -   Blue light: 450 nm to 495 nm;     -   Green light 495 nm to 570 nm;     -   Yellow light: 570 nm to 590 nm;     -   Orange light: 590 nm to 620 nm;     -   Red light: 620 nm to 750 nm; and     -   Infrared light (IR): 750 nm to 2500 nm,         wherein the wavelengths above are in nanometers (nm).

It should also be noted that there is typically some wavelength overlap between adjacent colors of light emitted by an LED. For example, wavelengths of blue and green light emitted by an LED typically overlap in a wavelength range of about 485 nanometers to about 505 nanometers. Further, wavelengths of blue and violet light emitted by an LED typically overlap in a wavelength range of about 440 nm to about 460 nm. In this way, the wavelength range of blue light is between about 450 nm to about 495 nm, and the wavelength range of green light is between about 495 nm to about 570 nm.

should be noted that an LED emits light in response to being activated, and an LED does not emit light in response to being deactivated. An LED is activated in response to driving a current through it to a current level above a threshold current level. Further, an LED is deactivated in response to driving a current through it to a current level below the threshold current level. In this embodiment, an LED of LED array 102 is activated in response to receiving a signal from LED controller 130, as will be discussed in more detail below.

It should be noted that the light emitted by two different types of LEDs of LED array 102 are mixed together. In this way, lighting system 100 a provides color mixing. The light of the LEDs of LED array 102 can be mixed together to provide a desired wavelength spectrum of light.

It should also be noted that the intensity of the light emitted by a single LED typically has a Gaussian wavelength distribution. However, some LEDs, such as those which provide white light, have intensities that have non-Gaussian wavelength distributions. An LED which provides white light and has an intensity having a non-Gaussian wavelength distribution will be discussed in more detail below with FIG. 9 g.

The wavelength spectrum of the light emitted by an LED can be chosen in response to choosing the band gap energy of the semiconductor material of the LED. The band gap energy of the semiconductor material of the LED is typically chosen by choosing the semiconductor material composition. The semiconductor material composition can be chosen during growth. It should be noted that the wavelength distribution of the light emitted by an LED can be chosen in response to choosing the semiconductor material composition. The semiconductor materials included with different types of LEDs can be of many different types, several of which will be discussed in more detail presently.

LEDs which emit IR light can include many different types of semiconductor materials, such as gallium arsenide and aluminum gallium arsenide. Further, LEDs which emit red light can include many different types of semiconductor materials, such as aluminum gallium arsenide, gallium arsenide phosphide, aluminum gallium indium phosphide and gallium phosphide.

LEDs which emit orange light can include many different types of semiconductor materials, such as gallium arsenide phosphide, aluminum gallium indium phosphide and gallium phosphide. Further, LEDs which emit yellow light can include many different types of semiconductor materials, such as gallium arsenide phosphide, aluminum gallium indium phosphide and gallium phosphide.

LEDs which emit green light can include many different types of semiconductor materials, such as indium gallium nitride/gallium nitride heterostructure, gallium phosphide, aluminum gallium indium phosphide and aluminum gallium phosphide. Further, LEDs which emit blue light can include many different types of semiconductor materials, such as zinc selenide and indium gallium nitride.

LEDs which emit violet light can include many different types of semiconductor materials, such as indium gallium nitride. Further, LEDs which emit ultraviolet light can include many different types of semiconductor materials, such as aluminum nitride, aluminum gallium nitride, and aluminum gallium indium nitride.

LEDs which emit purple light typically include a blue LED coated with a red phosphor or a white LED coated with a purple plastic. LEDs which emit white light can include a blue LED coated with a yellow phosphor.

Hence, the LEDs of LED array 102 can provide light having many different wavelength values, such as those mentioned above. The LEDs of LED array 102 can be provided by many different manufacturers, such as Cree, Inc. of Durham, N.C. and Nichia Corporation of Tokyo, Japan. In this particular embodiment, however, the LEDs of LED array 102 are provided by Philips Lumileds Lighting Company and are referred to as Luxeon-III light emitting diodes.

In operation, power supply 108 provides power signal S_(Power) to LED controller 130 through power terminal 108 a. LED controller 130 selectively controls the operation of the LEDs of LED array 102 in response to an indication from inputs 110 and/or 111, as will be discussed in more detail below. LED controller 130 selectively controls the operation of the LEDs of LED array 102 by controlling which types of LEDs are activated and deactivated. As mentioned above, activated LEDs emit light, and deactivated LEDs do not emit light. In this way, LED array 102 is capable of selectively emitting light of different wavelength ranges.

In one embodiment, LED array 102 includes a first LED which emits red light and a second LED which emits blue light. In this embodiment, LED array 102 can provide red light, blue light and a mixture of red and blue light in response to adjusting inputs 110 and/or 111.

In another embodiment, LED array 102 includes a first LED which emits violet light and a second LED which emits red light. In this embodiment, LED array 102 can provide violet light, red light and a mixture of violet and red light in response to adjusting inputs 110 and/or 111.

In one embodiment, LED array 102 includes a first LED which emits violet light and a second LED which emits blue light. In this embodiment, LED array 102 can provide violet light, blue light and a mixture of violet and blue light in response to adjusting inputs 111 and/or 110.

FIG. 1 b is a more detailed block diagram of lighting system 100 a, and FIG. 1 c is a more detailed front view of one embodiment of LED array 102. In this embodiment, LED controller 130 includes an LED sub-controller 131, which is operatively coupled to inputs 110 and 111, as well as to LED array 102. In particular, LED sub-controller 131 includes LED driver circuits 140 and 141, and LED array 102 includes LED sub-arrays 120 and 121. Input 110 is operatively coupled to LED sub-array 120 through LED driver circuit 140, and input 111 is operatively coupled to LED sub-array 121 through LED driver circuit 141. In this way, inputs 110 and 111 are operatively coupled to LED array 102 through LED controller 130.

In this embodiment, LED array 102 includes an LED array support structure 106 a which carries LED sub-arrays 120 and 121. In this embodiment, LED sub-array 120 includes one or more LEDs of the same type. Further, in this embodiment, LED sub-array 121 includes one or more LEDs of the same type. The LEDs of LED sub-array 120 are denoted as LEDs 120 a, and the LEDs of LED sub-array 121 are denoted as LEDs 121 a. In this embodiment, and for illustrative purposes, LEDs 120 a is capable of emitting blue light 162 and LEDs 121 a is capable of emitting red light 166. It should be noted that, in general, LED array 102 includes one or more LED sub-arrays. However, two LED sub-arrays are shown in FIG. 1 c for simplicity and ease of discussion. An embodiment in which LED array 102 includes five LED sub-arrays will be discussed in more detail below.

In operation, power supply 108 (FIG. 1 a) provides power signal S_(Power) to LED driver circuits 140 and 141 through power terminal 108 a (FIG. 1 a). Input 110 provides an input signal S_(Input1) to LED driver circuit 140 and, in response, LED driver circuit 140 provides an output signal S_(Output1) to LED sub-array 120. Further, input 111 provides an input signal S_(Input2) to LED driver circuit 141 and, in response, LED driver circuit 141 provides an output signal S_(Output2) to LED sub-array 121.

In some embodiments, input 110 operates as a switch, which is repeatably movable between active and deactive conditions. In some situations, input 110 is activated so that input signal S_(Input1) provides an indication to LED driver circuit 140 that it is desirable to activate the LEDs of LED sub-array 120. In response to the indication that it is desirable to activate the LEDs of LED sub-array 120, LED driver circuit 140 provides output signal S_(Output1) to LED sub-array 120, and LEDs 120 a are activated so they emit light.

In some situations, input 110 is deactivated so that input signal S_(Input1) provides an indication to LED driver circuit 140 that it is desirable to deactivate the LEDs of LED sub-array 120. In response to the indication that it is desirable to deactivate the LEDs of LED sub-array 120, LED driver circuit 140 provides output signal S_(Output1) to LED sub-array 120, and LEDs 120 a are deactivated so they do not emit blue light 162.

In some embodiments, input 111 operates as a switch, which is repeatably movable between active and deactive conditions. In some situations, input 111 is activated so that input signal S_(Input2) provides an indication to LED driver circuit 141 that it is desirable to activate the LEDs of LED sub-array 121. In response to the indication that it is desirable to activate the LEDs of LED sub-array 121, LED driver circuit 141 provides output signal S_(Output2) to LED sub-array 121, and LEDs 121 a are activated so they emit red light 166.

In some situations, input 111 is deactivated so that input signal S_(Input2) provides an indication to LED driver circuit 141 that it is desirable to deactivate the LEDs of LED sub-array 121. In response to the indication that it is desirable to deactivate the LEDs of LED sub-array 121, LED driver circuit 141 provides output signal S_(Output2) to LED sub-array 121, and LEDs 121 a are deactivated so they do not emit red light 166. In this way, LED array 102 is capable of selectively emitting light of different wavelength ranges.

FIG. 2 a is a schematic diagram of input 110 operatively coupled to LED sub-array 120 through LED driver circuit 140, wherein input 110 operates as a potentiometer. In this embodiment, input 110 includes a potentiometer 137 a, which is connected between power terminal 108 a and a current return 136. LED driver circuit 140 includes an LED driver chip 150, which is embodied as an LT3477EFE chip manufactured by Linear Technology, Inc. of Milpitas, Calif. The LT3477EFE chip is connected to electrical components, such as a resistor, inductor, capacitor and a Schottky diode, so that it operates as an LED driver. More information regarding the LT3477EFE chip, and how it is connected to the electrical components to operate as an LED driver, can be found in a corresponding Data Sheet provided by Linear Technology, Inc.

In this embodiment, power terminal 108 a is connected to terminals 1 and 13 of the LT3477EFE chip, and the output of the potentiometer is connected to terminal 10 so that terminal 10 receives input signal S_(Input1). Terminal 14 of the LT3477EFE chip provides output signal S_(Output1) to LED sub-array 120. In particular, terminal 14 of the LT3477EFE chip provides output signal S_(Output1) to LED 120 a.

In operation, the power of input signal S_(Input1) is adjustable in response to adjusting potentiometer 137 a. In one situation, the power of input signal S_(Input1) is increased in response to adjusting potentiometer 137 a. LED driver circuit chip 150 increases the power of output signal S_(Output1) in response to the power of input signal S_(Input1) being increased by potentiometer 137 a. The intensity of blue light 162 emitted by LED 120 a increases in response to the amount of power of output signal S_(Output1) being increased by LED driver circuit chip 150.

In another situation, the power of input signal S_(Input1) is decreased in response to adjusting potentiometer 137 a. LED driver circuit chip 150 decreases the power of output signal S_(Output1) in response to the power of input signal S_(Input1) being decreased by potentiometer 137 a. The intensity of blue light 162 emitted by LED 120 a decreases in response to the amount of power of output signal S_(Output1) being decreased by LED driver circuit chip 150.

FIG. 2 b is a schematic diagram of input 111 operatively coupled to LED sub-array 121 through LED driver circuit 141, wherein input 111 operates as a potentiometer. In this embodiment, input 111 is embodied as a potentiometer 137 b, which is connected between power terminal 108 a and current return 136. LED driver circuit 141 includes an LED driver chip 151, which is embodied as the LT3477EFE chip described in more detail above. The LT3477EFE chip of LED driver chip 151 is connected to electrical components, such as a resistor, inductor, capacitor and a Schottky diode, so that it operates as an LED driver.

In this embodiment, power terminal 108 a is connected to terminals 1 and 13 of the LT3477EFE chip, and the output of the potentiometer is connected to terminal 10 so that terminal 10 receives input signal S_(Input2). Terminal 14 of the LT3477EFE chip provides output signal S_(Output2) to LED sub-array 121. In particular, terminal 14 of the LT3477EFE chip provides output signal S_(Output2) to LED 121 a.

In operation, the power of input signal S_(Input2) is adjustable in response to adjusting potentiometer 137 b. In one situation, the power of input signal S_(Input2) is increased in response to adjusting potentiometer 137 b. LED driver circuit chip 151 increases the power of output signal S_(Output2) in response to the power of input signal S_(Input2) being increased by potentiometer 137 b. The intensity of red light 166 emitted by LED 121 a increases in response to the amount of power of output signal S_(Output2) being increased by LED driver circuit chip 151.

In another situation, the power of input signal S_(Input2) is decreased in response to adjusting potentiometer 137 b. LED driver circuit chip 151 decreases the power of output signal S_(Output2) in response to the power of input signal S_(Input2) being decreased by potentiometer 137 b. The intensity of red light 166 emitted by LED 121 a decreases in response to the amount of power of output signal S_(Output2) being decreased by LED driver circuit chip 151.

FIG. 3 a is a graph of a wavelength spectrum 180 of light provided by lighting system 100 a. In FIG. 3 a, wavelength spectrum 180 corresponds to the intensity of light versus wavelength (nm). The intensity of light is denoted as I₁, I₂, I₃ and I₄, wherein I₁ is less than I₂, I₂ is less than I₃ and I₃ is less than I₄. The intensity of light can be determined in many different ways, such as by using a spectrometer.

In this situation, input 110 provides signal S_(Input1) to LED driver circuit 140 (FIGS. 1 b and 2 a), and LED driver circuit 140 provides signal S_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED 120 a. In this particular example, LED 120 a is an LED that emits blue light 162 when activated. As shown in FIG. 3 a, blue light 162 has a Gaussian wavelength spectrum 180 a between about 450 nm and 495 nm. In some examples, blue light 162 has a Gaussian wavelength spectrum 180 a between about 475 nm and 500 nm. In some examples, blue light 162 has a Gaussian wavelength spectrum 180 a between about 450 nm and 475 nm. It should be noted that the intensity of blue light 162 of wavelength spectrum 180 can be adjusted in many different ways, several of which will be discussed in more detail presently.

As mentioned above, in some embodiments, input 110 operates as a switch which is repeatably movable between activated and deactivated conditions. In these embodiments, the intensity of blue light 162 provided by LED sub-array 120 is adjustable in response to adjusting the number of LEDs 120 a. For example, the intensity of blue light 162 decreases, as indicated by wavelength spectrum 180 b, in response to decreasing the number of LEDs 120 a of LED sub-array 120. Further, the intensity of blue light 162 increases, as indicated by wavelength spectrum 180 c, in response to increasing the number of LEDs 120 a of LED sub-array 120.

Further, in other embodiments, input 110 includes potentiometer 137 a. In some situations, potentiometer 137 a is adjusted so the power of input signal S_(Input1) and output signal S_(Output1) are decreased, as discussed above with FIG. 2 a. The intensity of blue light 162 decreases, as indicated by wavelength spectrum 180 b, in response to decreasing the power of input signal S_(Input1) and output signal S_(Output1) with potentiometer 137 a.

In some situations, potentiometer 137 a is adjusted so the power of input signal S_(Input1) and output signal S_(Output1) are increased, as discussed above with FIG. 2 a. The intensity of blue light 162 increases, as indicated by wavelength spectrum 180 c, in response to increasing the power of input signal S_(Input1) and output signal S_(Output1) with potentiometer 137 a.

FIG. 3 b is a graph of a wavelength spectrum 181 of light provided by lighting system 100 a. In FIG. 3 b, wavelength spectrum 181 corresponds to the intensity of light versus wavelength (nm), as discussed above with wavelength spectrum 180.

In this situation, input 111 provides signal S_(Input1) to LED driver circuit 141 (FIGS. 1 b and 2 b), and LED driver circuit 141 provides signal S_(Output1) to LED sub-array 121, wherein LED sub-array 121 includes LED 121 a. In this particular example, LED 121 a is an LED that emits red light 166 when activated. As shown in FIG. 3 b, red light 166 has a Gaussian wavelength spectrum 181 a between about 650 nm and 750 nm. In some examples, red light 166 has a Gaussian wavelength spectrum 181 a between about 620 nm and 670 nm. In some examples, red light 166 has a Gaussian wavelength spectrum 181 a between about 700 nm and 750 nm. It should be noted that the intensity of red light 166 of wavelength spectrum 181 can be adjusted in many different ways, several of which will be discussed in more detail presently.

As mentioned above, in some embodiments, input 111 operates as a switch which is repeatably movable between activated and deactivated conditions. In these embodiments, the intensity of red light 166 provided by LED sub-array 121 is adjustable in response to adjusting the number of LEDs 121 a. For example, the intensity of red light 166 decreases, as indicated by wavelength spectrum 181 b, in response to decreasing the number of LEDs 121 a of LED sub-array 121. Further, the intensity of red light 166 increases, as indicated by wavelength spectrum 181 c, in response to increasing the number of LEDs 121 a of LED sub-array 121.

Further, in other embodiments, input 111 includes potentiometer 137 b. In some situations, potentiometer 137 b is adjusted so the power of input signal S_(Input2) and output signal S_(Output2) are decreased, as discussed above with FIG. 2 b. The intensity of red light 166 decreases, as indicated by wavelength spectrum 181 b, in response to decreasing the power of input signal S_(Input2) and output signal S_(Output2) with potentiometer 137 b.

In some situations, potentiometer 137 b is adjusted so the power of input signal S_(Input2) and output signal S_(Output2) are increased, as discussed above with FIG. 2 b. The intensity of red light 166 increases, as indicated by wavelength spectrum 181 c, in response to increasing the power of input signal S_(Input2) and output signal S_(Output2) with potentiometer 137 b.

As mentioned above, lighting system 100 a can provide color mixing when LED array 102 includes different types of LEDs. An example of a wavelength spectrum with color mixing will be discussed in more detail presently.

FIG. 3 c is a graph of a wavelength spectrum 182 of light provided by lighting system 100 a, wherein wavelength spectrum 182 includes color mixing. In FIG. 3 c, wavelength spectrum 182 corresponds to the intensity of light versus wavelength (nm), as discussed above with wavelength spectrum 180. As shown in FIG. 3 c, blue light 162 has a Gaussian wavelength spectrum 180 a between about 450 nm and 500 nm, and red light 166 has a Gaussian wavelength spectrum 181 a between about 650 nm and 750 nm. Lighting system 100 a can provide wavelength spectrum 182 with color mixing in many different ways.

In one embodiment, inputs 110 and 111 operate as switches, which are repeatably movable between activated and deactivated conditions. In these embodiments, the intensity of blue light 162 provided by LED sub-array 120 is adjustable in response to adjusting the number of LEDs 120 a. For example, the intensity of blue light 162 decreases, as indicated by wavelength spectrum 180 b, in response to decreasing the number of LEDs 120 a of LED sub-array 120. Further, the intensity of blue light 162 increases, as indicated by wavelength spectrum 180 c, in response to increasing the number of LEDs 120 a of LED sub-array 120.

In these embodiments, the intensity of red light 166 provided by LED sub-array 121 is adjustable in response to adjusting the number of LEDs 121 a. For example, the intensity of red light 166 decreases, as indicated by wavelength spectrum 181 b, in response to decreasing the number of LEDs 121 a of LED sub-array 121. Further, the intensity of red light 166 increases, as indicated by wavelength spectrum 181 c, in response to increasing the number of LEDs 121 a of LED sub-array 121.

It should be noted that the relative intensities of blue light 162 and red light 166 provided by lighting system 100 a can be adjusted relative to each other in response to adjusting the number of LEDs 120 a of LED sub-array 120 and the number of LEDs 121 a of LED sub-array 121. The relative intensities of blue light 162 and red light 166 can be adjusted in many different ways.

For example, in one situation, the number of LEDs 120 a can be increased relative to the number of LEDs 121 a, so that wavelength spectrum 180 c and wavelength spectrum 181 b are provided by LED sub-arrays 120 and 121, respectively. In this way, the amount of blue light 162 and red light 166 provided by lighting system 100 a is increased relative to the amount of red light 166. Further, the number of LEDs 121 a can be decreased relative to the number of LEDs 120 a, so that wavelength spectrum 180 c and wavelength spectrum 181 b are provided by LED sub-arrays 120 and 121, respectively. In this way, the amount of blue light 162 and red light 166 provided by lighting system 100 a is decreased relative to the amount of red light 166. In this way, lighting system 100 a is capable of providing a desired mixture of blue and red light.

In other embodiments, inputs 110 and 111 include potentiometers 136 a and 136 b, respectively. In some situations, potentiometer 137 a is adjusted so the power of input signal S_(Input1) and output signal S_(Output1) are decreased, as discussed above with FIG. 2 a. The intensity of blue light 162 decreases, as indicated by wavelength spectrum 180 b, in response to decreasing the power of input signal S_(Input1) and output signal S_(Output1) with potentiometer 137 a.

In some situations, potentiometer 137 a is adjusted so the power of input signal S_(Input1) and output signal S_(Output1) are increased, as discussed above with FIG. 2 a. The intensity of blue light 162 increases, as indicated by wavelength spectrum 180 c, in response to increasing the power of input signal S_(Input1) and output signal S_(Output1) with potentiometer 137 a.

In some situations, potentiometer 137 b is adjusted so the power of input signal S_(Input2) and output signal S_(Output2) are decreased, as discussed above with FIG. 2 b. The intensity of red light 166 decreases, as indicated by wavelength spectrum 181 b, in response to decreasing the power of input signal S_(Input2) and output signal S_(Output2) with potentiometer 137 b.

In some situations, potentiometer 137 b is adjusted so the power of input signal S_(Input2) and output signal S_(Output2) are increased, as discussed above with FIG. 2 b. The intensity of red light 166 increases, as indicated by wavelength spectrum 181 c, in response to increasing the power of input signal S_(Input2) and output signal S_(Output2) with potentiometer 137 b.

It should be noted that the relative intensities of blue light 162 and red light 166 can be adjusted relative to each other in response to adjusting potentiometers 136 a and/or 136 b. The relative intensities of blue light 162 and red light 166 can be adjusted in many different ways by adjusting potentiometers 136 a and 136 b.

For example, in some situations, it may be desirable to provide more blue light 162 and less red light 166 with lighting system 100 a. In this situation, potentiometer 137 a is adjusted, as described above, so that input signal S_(Input1) and output signal S_(Output1) have more power, and wavelength spectrum 180 c is provided by LED sub-array 120. Further, potentiometer 137 b is adjusted, as described above, so that input signal S_(Input2) and output signal S_(Output2) have less power, and wavelength spectrum 181 b is provided by LED sub-array 121. In this way, lighting system 100 a provides more blue light 162 and less red light 166.

In some situations, the intensity of red light 166 is about one order of magnitude greater than the intensity of blue light 162. In another situation, the intensity of red light 166 is about ten to about fifteen times greater than the intensity of blue light 162. In another situation, the intensity of red light 166 is about eight to thirteen times greater than the intensity of blue light 162. In general, the intensity of red light 166 is a desired amount greater than the intensity of blue light 162.

In some situations, the intensity of blue light 162 is about one order of magnitude greater than the intensity of red light 166. In another situation, the intensity of blue light 162 is about ten to about fifteen times greater than the intensity of red light 166. In another situation, the intensity of blue light 162 is about eight to thirteen times greater than the intensity of red light 166. In general, the intensity of blue light 162 is a desired amount greater than the intensity of red light 166.

In another situation, it may be desirable to provide less blue light 162 and more red light 166 with lighting system 100 a. In this situation, potentiometer 137 a is adjusted, as described above, so that input signal S_(Input1) and output signal S_(Output1) have less power, and wavelength spectrum 180 b is provided by LED sub-array 120. Further, potentiometer 137 b is adjusted, as described above, so that input signal S_(Input2) and output signal S_(Output2) have more power, and wavelength spectrum 181 c is provided by LED sub-array 121. In this way, lighting system 100 a provides less blue light 162 and more red light 166. It should be noted that the desired mixture of light provided by lighting system 100 a can be chosen to correspond to an action spectrum of a physiological activity of a plant, as will be discussed in more detail presently.

FIGS. 4 a and 4 b are graphs of wavelength spectrum 183 and 184, respectively, of light provided by lighting system 100 a. Action spectrum corresponding to chlorophyll a and chlorophyll b are also shown in FIGS. 4 a and 4 b, respectively. In FIGS. 4 a and 4 b, wavelength spectrums 183 and 184 correspond to the intensity of light versus wavelength (nm), as discussed above with wavelength spectrum 180.

It should be noted that the action spectrum of chlorophyll a and chlorophyll b of FIGS. 4 a and 4 b, respectively, as well as the other action spectra discussed herein, are from a book entitled Introduction to Plant Physiology, 2nd Edition, by William G. Hopkins, which was published in 1999 by John Wiley & Sons. An action spectrum is the rate of a physiological activity versus the wavelength of light received by a plant. An action spectrum illustrates which wavelengths of light are effective in driving the physiological activity, wherein the physiological activity corresponds to a chemical reaction of the plant. The physiological activity of the plant can be of many different types, such as the chemical reactions associated with photosynthesis and cellular respiration. The wavelengths of light that are effective in driving the physiological activity of the plant depends on the types of pigments the plant includes.

Plants can include many different types of pigments, such as chlorophylls, carotenoids and phycobilins. There are many different types of chlorophylls, such as chlorophyll a and chlorophyll b. Further, there are many different types of carotenoids, such as xanthophylls and carotenes. There are many different types of carotenes, such as α-carotene and β-carotene. There are many different types of phycobilins, such as pelargonidin, phycocyanin, phycoerythrin, phytochrome and anthocyanins, among others. It should also be noted that the action spectrum of chlorophyll a and chlorophyll b is similar to the action spectrum of other chemicals, such as those associated with leaf extract.

For example, the red and blue-violet spectrums of light are effective in driving the physiological activity of photosynthesis of chlorophyll a and chlorophyll b. Hence, the action spectrum corresponding to chlorophyll a and chlorophyll b are non-zero in a range of wavelengths that include red and blue-violet light. In this way, the rate of photosynthesis of chlorophyll a and chlorophyll b increases in response to receiving more red and blue-violet light. Further, the rate of photosynthesis of chlorophyll a and chlorophyll b decreases in response to receiving less red and blue-violet light.

In the situation of FIG. 4 a, input 110 provides signal S_(Input1) to LED driver circuit 140, and LED driver circuit 140 provides signal S_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED 120 a. In this particular example, LED 120 a is an LED that emits violet light 161 when activated. As shown in FIG. 4 a, violet light 161 has a Gaussian wavelength spectrum 183 a between about 400 nm and 450 nm. In some examples, violet light 161 has a Gaussian wavelength spectrum 183 a between about 380 nm and 425 nm. In some examples, violet light 161 has a Gaussian wavelength spectrum 183 a between about 425 nm and 450 nm.

Further, in this situation, input 111 provides signal S_(Input2) to LED driver circuit 141, and LED driver circuit 141 provides signal S_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED 121 a. In this particular example, LED 121 a is an LED that emits red light 166 when activated. As shown in FIG. 4 a, red light 166 has a Gaussian wavelength spectrum 183 b between about 650 nm and 675 nm. In this way, lighting system 100 a is capable of providing a wavelength spectrum which corresponds to the action spectrum of chlorophyll a when lighting system 100 a includes LEDs capable of emitting violet light 161 and red light 166.

As mentioned above, the intensity of the light provided by the different types of LEDs of lighting system 100 a are adjustable relative to each other. In one embodiment, inputs 110 and 111 correspond to switches so that the intensity of violet light 161 provided by LED sub-array 120 is adjusted by adjusting the number of LEDs 120 a. Further, the intensity of red light 166 provided by LED sub-array 121 is adjusted by adjusting the number of LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so that the intensity of violet light 161 provided by LED sub-array 120 is adjusted by adjusting potentiometer 137 a, as described in more detail above. Further, input 111 includes potentiometer 137 b, so that the intensity of red light 166 provided by LED sub-array 121 is adjusted by adjusting potentiometer 137 b, as described in more detail above. It should be noted that the relative intensities of violet light 161 and red light 166 can be adjusted relative to each other in response to adjusting potentiometers 136 a and 136 b. In some situations, the intensity of red light 166 is about ten to about fifteen times greater than the intensity of violet light 161.

In the situation of FIG. 4 b, input 110 provides signal S_(Input1) to LED driver circuit 140, and LED driver circuit 140 provides signal S_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED 120 a. In this particular example, LED 120 a is an LED that emits blue-violet light 170 when activated. As shown in FIG. 4 b, blue-violet light 170 has a Gaussian wavelength spectrum 184 a between about 400 nm and 475 nm. In some examples, blue-violet light 170 has a Gaussian wavelength spectrum 184 a between about 450 nm and 500 nm.

Further, in this situation, input 111 provides signal S_(Input2) to LED driver circuit 141, and LED driver circuit 141 provides signal S_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED 121 a. In this particular example, LED 121 a is an LED that emits red light 166 when activated. As shown in FIG. 4 b, red light 166 has a Gaussian wavelength spectrum 184 b between about 625 nm and 675 nm. In this way, lighting system 100 a is capable of providing a wavelength spectrum which corresponds to the action spectrum of chlorophyll b when lighting system 100 a includes LEDs capable of emitting blue-violet light 170 and red light 166.

As mentioned above, the intensity of the light provided by the different types of LEDs of lighting system 100 a are adjustable relative to each other. In one embodiment, inputs 110 and 111 correspond to switches so that the intensity of blue-violet light 170 provided by LED sub-array 120 is adjusted by adjusting the number of LEDs 120 a. Further, the intensity of red light 166 provided by LED sub-array 121 is adjusted by adjusting the number of LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so that the intensity of blue-violet light 170 provided by LED sub-array 120 is adjusted by adjusting potentiometer 137 a, as described in more detail above. Further, input 111 includes potentiometer 137 b, so that the intensity of red light 166 provided by LED sub-array 121 is adjusted by adjusting potentiometer 137 b, as described in more detail above. It should be noted that the relative intensities of blue-violet light 170 and red light 166 can be adjusted relative to each other in response to adjusting potentiometers 136 a and 136 b.

In general, the types of LEDs of lighting system 100 a are chosen so that lighting system 100 a can provide a wavelength spectrum which drives the physiological activity of a desired type of plant. Hence, lighting system 100 a can provide wavelength spectra useful for plants which have action spectrum different from chlorophyll a and chlorophyll b, as will be discussed in more detail presently.

FIGS. 4 c and 4 d are graphs of wavelength spectrum 185 and 186, respectively, of light provided by lighting system 100 a. Action spectrum corresponding to α-carotene are also shown in FIGS. 4 c and 4 d. FIGS. 4 e and 4 f are graphs of wavelength spectrum 187 and 188, respectively, of light provided by lighting system 100 a. Action spectrum corresponding to β-carotene are also shown in FIGS. 4 e and 4 f. In FIGS. 4 c, 4 d, 4 e and 4 f, the wavelength spectrums correspond to the intensity of light versus wavelength (nm), as discussed above with wavelength spectrum 180.

The physiological activity of α-carotene and β-carotene is effectively driven by wavelengths of blue-violet light. Hence, the action spectrum corresponding to α-carotene and β-carotene are non-zero in a range of wavelengths that include blue and violet light. In this way, the rate of physiological activity of α-carotene and β-carotene increases in response to receiving more blue-violet light. Further, the rate of physiological activity of α-carotene and β-carotene decreases in response to receiving less blue-violet light.

In the situation of FIG. 4 c, input 110 provides signal S_(Input1) to LED driver circuit 140, and LED driver circuit 140 provides signal S_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED 120 a. In this particular example, LED 120 a is an LED that emits violet light 161 when activated. As shown in FIG. 4 c, violet light 161 has a Gaussian wavelength spectrum 185 a between about 400 nm and 450 nm.

Further, in this situation, input 111 provides signal S_(Input2) to LED driver circuit 141, and LED driver circuit 141 provides signal S_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED 121 a. In this particular example, LED 121 a is an LED that emits blue light 162 when activated. As shown in FIG. 4 c, blue light 162 has a Gaussian wavelength spectrum 185 b between about 425 nm and 475 nm. In this way, lighting system 100 a is capable of providing a wavelength spectrum which corresponds to the action spectrum of α-carotene when lighting system 100 a includes LEDs capable of emitting violet light 161 and blue light 162.

As mentioned above, the intensity of the light provided by the different types of LEDs of lighting system 100 a are adjustable relative to each other. In one embodiment, inputs 110 and 111 correspond to switches so that the intensity of violet light 161 provided by LED sub-array 120 is adjusted by adjusting the number of LEDs 120 a. Further, the intensity of blue light 162 provided by LED sub-array 121 is adjusted by adjusting the number of LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so that the intensity of violet light 161 provided by LED sub-array 120 is adjusted by adjusting potentiometer 137 a, as described in more detail above. Further, input 111 includes potentiometer 137 b, so that the intensity of blue light 162 provided by LED sub-array 121 is adjusted by adjusting potentiometer 137 b, as described in more detail above. It should be noted that the relative intensities of violet light 161 and blue light 162 can be adjusted relative to each other in response to adjusting potentiometers 136 a and 136 b. It should also be noted that the physiological activity of α-carotene can be driven in response to the light from one type of LED, as will be discussed in more detail presently.

In the situation of FIG. 4 d, input 110 provides signal S_(Input1) to LED driver circuit 140, and LED driver circuit 140 provides signal S_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED 120 a. In this particular example, LED 120 a is an LED that emits blue-violet light 170 when activated. As shown in FIG. 4 d, blue-violet light 170 has a Gaussian wavelength spectrum 186 a between about 400 nm and 500 nm. In this way, LED 120 a provides blue-violet light 170 which has a broader spectrum than the spectrum of violet light 161 FIG. 4 c. Further, LED 120 a provides blue-violet light 170 which has a broader spectrum than the spectrum of blue light 162 FIG. 4 c. As mentioned above, the wavelength distribution of light provided by an LED can be made broader and narrower in many different ways, such as by choosing the semiconductor material composition of the LED.

Further, in this situation, input 111 provides input signal S_(Input2) to LED driver circuit 141, and LED driver circuit 141 provides output signal S_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED 121 a. In this particular example, LED 121 a is deactivated in response to receiving output signal S_(Output2) In this way, the physiological activity of α-carotene is driven in response to the light from one type of LED.

In one embodiment, inputs 110 and 111 correspond to switches so that the intensity of blue-violet light 170 provided by LED sub-array 120 is adjusted by adjusting the number of LEDs 120 a. Further, the intensity of blue light 162 provided by LED sub-array 121 is adjusted by deactivating LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so that the intensity of blue-violet light 170 provided by LED sub-array 120 is adjusted by adjusting potentiometer 137 a, as described in more detail above. Further, input 111 includes potentiometer 137 b, so that the intensity of blue light 162 provided by LED sub-array 121 is adjusted by adjusting potentiometer 137 b so that output signal S_(Output2) deactivates LEDs 121 a.

In the situation of FIG. 4 e, input 110 provides signal S_(Input1) to LED driver circuit 140, and LED driver circuit 140 provides signal S_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED 120 a. In this particular example, LED 120 a is an LED that emits blue-violet light 170 when activated. As shown in FIG. 4 e, blue-violet light 170 has a Gaussian wavelength spectrum 187 a between about 425 nm and 475 nm.

Further, in this situation, input 111 provides signal S_(Input2) to LED driver circuit 141, and LED driver circuit 141 provides signal S_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED 121 a. In this particular example, LED 121 a is an LED that emits blue light 162 when activated. As shown in FIG. 4 e, blue light 162 has a Gaussian wavelength spectrum 187 b between about 425 nm and 475 nm. In this way, lighting system 100 a is capable of providing a wavelength spectrum which corresponds to the action spectrum of β-carotene when lighting system 100 a includes LEDs capable of emitting blue-violet light 170 and blue light 162.

As mentioned above, the intensity of the light provided by the different types of LEDs of lighting system 100 a are adjustable relative to each other. In one embodiment, inputs 110 and 111 correspond to switches so that the intensity of blue-violet light 170 provided by LED sub-array 120 is adjusted by adjusting the number of LEDs 120 a. Further, the intensity of blue light 162 provided by LED sub-array 121 is adjusted by adjusting the number of LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so that the intensity of blue-violet light 170 provided by LED sub-array 120 is adjusted by adjusting potentiometer 137 a, as described in more detail above. Further, input 111 includes potentiometer 137 b, so that the intensity of blue light 162 provided by LED sub-array 121 is adjusted by adjusting potentiometer 137 b, as described in more detail above. It should be noted that the relative intensities of blue-violet light 170 and blue light 162 can be adjusted relative to each other in response to adjusting potentiometers 136 a and 136 b. It should also be noted that the physiological activity of β-carotene can be driven in response to the light from one type of LED, as will be discussed in more detail presently.

In the situation of FIG. 4 f, input 110 provides signal S_(Input1) to LED driver circuit 140, and LED driver circuit 140 provides signal S_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED 120 a. In this particular example, LED 120 a is an LED that emits blue-violet light 170 when activated. As shown in FIG. 4 f, blue-violet light 170 has a Gaussian wavelength spectrum 188 a between about 400 nm and 500 nm. In this way, LED 120 a provides blue-violet light 170 which has a broader spectrum than the spectrum of violet light 161 FIG. 4 e. Further, LED 120 a provides blue-violet light 170 which has a broader spectrum than the spectrum of blue light 162 FIG. 4 e. As mentioned above, the wavelength distribution of light provided by an LED can be made broader and narrower in many different ways, such as by choosing the semiconductor material composition of the LED.

Further, in this situation, input 111 provides input signal S_(Input2) to LED driver circuit 141, and LED driver circuit 141 provides output signal S_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED 121 a. In this particular example, LED 121 a is deactivated in response to receiving output signal S_(Output2) In this way, the physiological activity of β-carotene is driven in response to the light from one type of LED.

In one embodiment, inputs 110 and 111 correspond to switches so that the intensity of blue-violet light 170 provided by LED sub-array 120 is adjusted by adjusting the number of LEDs 120 a. Further, the intensity of blue light 162 provided by LED sub-array 121 is adjusted by deactivating LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so that the intensity of blue-violet light 170 provided by LED sub-array 120 is adjusted by adjusting potentiometer 137 a, as described in more detail above. Further, input 111 includes potentiometer 137 b, so that the intensity of light provided by LED sub-array 121 is adjusted by adjusting potentiometer 137 b so that output signal S_(Ooutput2) deactivates LEDs 121 a.

FIG. 4 g is a graph of wavelength spectrum 189 of light provided by lighting system 100 a. Action spectrum corresponding to pelargonin (Perlargonidin-3,5-diglucoside) is also shown in FIG. 4 g. In FIG. 4 g, wavelength spectrum 189 corresponds to the intensity of light versus wavelength (nm), as discussed above with wavelength spectrum 180.

In the situation of FIG. 4 g, input 110 provides signal S_(Input1) to LED driver circuit 140, and LED driver circuit 140 provides signal S_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED 120 a. In this particular example, LED 120 a is an LED that emits blue-green light 171 when activated. As shown in FIG. 4 g, blue-green light 171 has a Gaussian wavelength spectrum 189 a between about 450 nm and 550 nm. In this way, LED 120 a provides blue-green light 171 which has a broader spectrum than the spectrum of blue light 162 FIG. 4 e. As mentioned above, the wavelength distribution of light provided by an LED can be made broader and narrower in many different ways, such as by choosing the semiconductor material composition of the LED.

Further, in this situation, input 111 provides input signal S_(Input2) to LED driver circuit 141, and LED driver circuit 141 provides output signal S_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED 121 a. In this particular example, LED 121 a is deactivated in response to receiving output signal S_(Output2) In this way, the physiological activity of pelargonin is driven in response to the light from one type of LED.

In one embodiment, inputs 110 and 111 correspond to switches so that the intensity of blue-green light 171 provided by LED sub-array 120 is adjusted by adjusting the number of LEDs 120 a. Further, the intensity of blue-green light 171 provided by LED sub-array 121 is adjusted by deactivating LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so that the intensity of light provided by LED sub-array 120 is adjusted by adjusting potentiometer 137 a, as described in more detail above. Further, input 111 includes potentiometer 137 b, so that the intensity of light provided by LED sub-array 121 is adjusted by adjusting potentiometer 137 b so that output signal S_(Output2) deactivates LEDs 121 a.

It should be noted that the broadness of the wavelength spectra of blue-green light 171 can be chosen by choosing the semiconductor material of LEDs 120 a, as discussed above with FIG. 4 f. Further, it should be noted that, in some embodiments, LEDs 121 a emit green light 163 and are activated so that green light 163 is mixed with blue-green light 171. In this way, wavelength spectrum 189 corresponds to the wavelength spectra of two different types of LEDs, as discussed above with FIG. 4 e.

FIG. 4 h is a graph of wavelength spectrum 190 of light provided by lighting system 100 a. Action spectrum corresponding to phycocyanin is also shown in FIG. 4 h. In FIG. 4 h, wavelength spectrum 190 corresponds to the intensity of light versus wavelength (nm), as discussed above with wavelength spectrum 180.

In the situation of FIG. 4 h, input 110 provides signal S_(Input1) to LED driver circuit 140, and LED driver circuit 140 provides signal S_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED 120 a. In this particular example, LED 120 a is an LED that emits yellow-orange light 172 when activated. As shown in FIG. 4 h, yellow-orange light 172 has a Gaussian wavelength spectrum 189 a between about 575 nm and 625 nm.

Further, in this situation, input 111 provides input signal S_(Input2) to LED driver circuit 141, and LED driver circuit 141 provides output signal S_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED 121 a. In this particular example, LED 121 a is deactivated in response to receiving output signal S_(Output2). In this way, the physiological activity of pelargonin is driven in response to the light from one type of LED.

In one embodiment, inputs 110 and 111 correspond to switches so that the intensity of yellow-orange light 172 provided by LED sub-array 120 is adjusted by adjusting the number of LEDs 120 a. Further, the intensity of yellow-orange light 172 provided by LED sub-array 121 is adjusted by deactivating LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so that the intensity of yellow-orange light 172 provided by LED sub-array 120 is adjusted by adjusting potentiometer 137 a, as described in more detail above. Further, input 111 includes potentiometer 137 b, so that the intensity of light provided by LED sub-array 121 is adjusted by adjusting potentiometer 137 b so that output signal S_(Ooutput2) deactivates LEDs 121 a. It should be noted that the broadness of the wavelength spectra of yellow-orange light 172 can be chosen by choosing the semiconductor material of LEDs 120 a, as discussed above with FIG. 4 f.

FIG. 4 i is a graph of wavelength spectrum 191 of light provided by lighting system 100 a. Action spectrum corresponding to phycoerythrin is also shown in FIG. 4 i. In FIG. 4 i, wavelength spectrum 191 corresponds to the intensity of light versus wavelength (nm), as discussed above with wavelength spectrum 180.

In the situation of FIG. 4 i, input 110 provides signal S_(Input1) to LED driver circuit 140, and LED driver circuit 140 provides signal S_(Output1) to LED sub-array 120, wherein LED sub-array 120 includes LED 120 a. In this particular example, LED 120 a is an LED that emits blue-green light 171 when activated. As shown in FIG. 4 i, blue-green light 171 has a Gaussian wavelength spectrum 181 a between about 475 nm and 550 nm.

Further, in this situation, input 111 provides input signal S_(Input2) to LED driver circuit 141, and LED driver circuit 141 provides output signal S_(Output2) to LED sub-array 121, wherein LED sub-array 121 includes LED 121 a. In this particular example, LED 121 a emits green light 163 when activated. As shown in FIG. 4 i, green light 163 has a Gaussian wavelength spectrum 191 b between about 500 nm and 575 nm. In this way, the physiological activity of phycoerythrin is driven in response to the light from two types of LEDs.

In one embodiment, inputs 110 and 111 correspond to switches so that the intensity of blue-green light 171 provided by LED sub-array 120 is adjusted by adjusting the number of LEDs 120 a. Further, the intensity of green light 163 provided by LED sub-array 121 is adjusted by adjusting the number of LEDs 121 a.

In another embodiment, input 110 includes potentiometer 137 a, so that the intensity of blue-green light 171 provided by LED sub-array 120 is adjusted by adjusting potentiometer 137 a, as described in more detail above. Further, input 111 includes potentiometer 137 b, so that the intensity of green light 163 provided by LED sub-array 121 is adjusted by adjusting potentiometer 137 b, as described in more detail above. It should be noted that the broadness of the wavelength spectra of blue-green light 171 and/or green light 163 can be chosen by choosing the semiconductor material of LEDs 120 a and 121 a, respectively, as discussed in more detail above.

As mentioned above, the lighting system can include one or more LED sub-arrays, which include different types of LEDs. As will be discussed in more detail presently, the type of LEDs of the sub-arrays can be chosen so that the lighting system can provide a desired wavelength spectrum between UV light and IR light, which is useful to drive the physiological activity of a plant.

FIGS. 5 a and 5 b are bottom and top perspective views, respectively, of a lighting system 100 b. In this embodiment, lighting system 100 b includes inputs 110, 111, 112, 113 and 114 (FIG. 5 b) operatively coupled to LED arrays 102 and 103 through LED controller 130 (not shown). As discussed in more detail below, LED arrays 102 and 103 each include LED sub-arrays connected to inputs 110-114. The LED sub-arrays of LED arrays 102 and 103 each include a plurality of LEDs, as will be discussed in more detail with FIGS. 5 f and 5 g. The LEDs of arrays 102 and 103 can be of many different types, such as those mentioned above.

LED arrays 102 and 103 are spaced apart from each other by a distance L (FIG. 5 b) so that lighting system 100 b provides a desired intensity of light away from LED arrays 102 and 103. LED arrays 102 and 103 are spaced apart from each other by distance L so that lighting system 100 b can be more effectively cooled, as will be discussed in more detail below. It should be noted that, in this embodiment, LED arrays 102 and 103 include the same number of LEDs. However, in other embodiments, LED arrays 102 and 103 can include different numbers of LEDs. For example, in one embodiment, LED array 102 includes twenty five LEDs and LED array 103 includes twenty six LEDs.

In this embodiment, lighting system 100 b includes a lighting system housing 101 which houses LED arrays 102 and 103. FIGS. 5 c and 5 d are top and back perspective views of lighting system 100 b with and without lighting system housing 101, respectively. FIG. 5 e is a front perspective view of lighting system 100 b without lighting system housing 101. As shown in FIGS. 5 c and 5 d, lighting system 100 b includes an on/off switch 109 operatively coupled with LED controller 130. On/off switch 109 is for turning LED controller 130 on and off.

As shown in FIGS. 5 a, 5 b, 5 d and 5 e, lighting system 100 b includes fans 104 a and 104 b which provide cooling. For example, fans 104 a and 104 b can cool LED controller 130 (not shown) and LED arrays 102 and 103. Fans 104 a and 104 b can be positioned at many different locations of lighting system 100 b. In this embodiment, fans 104 a and 104 b are positioned between LED arrays 102 and 103.

As shown in FIGS. 5 d and 5 e, lighting system 100 includes a heatsinks 105 a and 105 b which provide cooling for LED arrays 102 and 103, respectively. Heatsinks 105 a and 105 b also provide cooling for LED controller 130. As mentioned above, LED arrays 102 and 103 are spaced apart from each other by distance L, which allows LED arrays 102 and 103 to be more effectively cooled by fans 104 a and 104 b, and corresponding heatsinks 105 a and 105 b.

FIG. 5 f is a front view of LED array 102 of lighting system 100 b, wherein LED array 102 includes LED sub-arrays 120, 121, 122, 123 and 124 carried by LED array support structure 106 a. LED array 102 generally includes one or more LED sub-array arrays, but it includes five LED sub-arrays in this embodiment for illustrative purposes. An embodiment in which LED array 102 includes two LED sub-arrays is discussed in more detail above.

In this embodiment, LED sub-arrays 120, 121, 122, 123 and 124 each include five LEDs for illustrative purposes so that LED array 102 includes twenty five LEDs. However, as discussed in more detail above with FIG. 1 c, LED array 102 includes two or more sub-arrays LEDs, and the LED sub-arrays generally include one or more LEDs.

In this embodiment, LED sub-array 120 includes LEDs 120 a, 120 b, 120 c, 120 d and 120 e, and LED sub-array 121 includes LEDs 121 a, 121 b, 121 c, 121 d and 121 e. LED sub-array 122 includes LEDs 122 a, 122 b, 122 c, 122 d and 122 e, and LED sub-array 123 includes LEDs 123 a, 123 b, 123 c, 123 d and 123 e. Further, LED sub-array 124 includes LEDs 124 a, 124 b, 124 c, 124 d and 124 e. The light emitting diodes included with LED array 102 can emit many different colors of light in response to output signals received from LED controller 130, as will be discussed in more detail below with FIGS. 9 a-9 f.

FIG. 5 g is a front view of LED array 103 of lighting system 100 b, wherein LED array 103 includes LED sub-arrays 125, 126, 127, 128 and 129 carried by LED array support structure 106 b. LED array 103 generally includes one or more LED sub-arrays, but it includes five LED sub-arrays in this embodiment for illustrative purposes. An embodiment in which LED array 103 includes two LED sub-arrays is discussed in more detail above.

In this embodiment, LED sub-arrays 125, 126, 127, 128 and 129 each include five LEDs for illustrative purposes so that LED array 103 includes twenty five LEDs. However, as discussed in more detail above with FIG. 1 c, LED array 103 includes two or more LEDs, and LED sub-arrays generally include one or more LEDs.

In this embodiment, LED sub-array 125 includes LEDs 125 a, 125 b, 125 c, 125 d and 125 e, and LED sub-array 126 includes LEDs 126 a, 126 b, 126 c, 126 d and 126 e. LED sub-array 127 includes LEDs 127 a, 127 b, 127 c, 127 d and 127 e, and LED sub-array 128 includes LEDs 128 a, 128 b, 128 c, 128 d and 128 e. Further, LED sub-array 129 includes LEDs 129 a, 129 b, 129 c, 129 d and 129 e. The light emitting diodes included with LED array 103 can emit many different colors of light in response to output signals received from LED controller 130, as will be discussed in more detail below with FIGS. 9 a-9 f.

In this particular embodiment, LED sub-arrays 120 and 125 include LEDs which are capable of emitting UV light 160. Hence, LEDs 120 a-120 e and LEDs 125 a-125 e are capable of emitting UV light 160. In some embodiments, UV light 160 has a wavelength between about 300 and 380 nm. In other embodiments, IR light 167 has a wavelength between about 350 and 380 nm.

LED sub-arrays 121 and 126 include LEDs which are capable of emitting blue light 162. Hence, LEDs 121 a-121 e and LEDs 126 a-126 e are capable of emitting blue light 162. LED sub-arrays 122 and 127 include LEDs which are capable of emitting green light 163. Hence, LEDs 122 a-122 e and LEDs 127 a-127 e are capable of emitting green light 163. LED sub-arrays 123 and 128 include LEDs which are capable of emitting red light 166. Hence, LEDs 123 a-123 e and LEDs 128 a-128 e are capable of emitting red light 166. LED sub-arrays 124 and 129 include LEDs which are capable of emitting IR light 167. Hence, LEDs 124 a-124 e and LEDs 129 a-129 e are capable of emitting IR light 167. In some embodiments, IR light 167 has a wavelength between about 750 and 825 nm. In other embodiments, IR light 167 has a wavelength between about 750 and 900 nm.

FIGS. 6 a and 6 b are block diagram of lighting system 100 b, which includes inputs 110-114 operatively coupled to LED arrays 102 and 103 through LED controller 130, wherein LED controller 130 includes LED sub-controllers 131 and 132. In this embodiment, and as shown in FIG. 6 a, LED sub-controller 131 is operatively coupled to inputs 110, 111, 112, 113 and 114, as well as to LED array 102. In this embodiment, LED sub-controller 131 includes LED driver circuits 140, 141, 142, 143 and 144 operatively coupled to LED sub-arrays 120, 121, 122, 123 and 124, respectively. Further, inputs 110, 111, 112, 113 and 114 are operatively coupled with LED driver circuits 140, 141, 142, 143 and 144, respectively.

In operation, input 110 provides input signal S_(Input1) to LED driver circuit 140 and, in response, LED driver circuit 140 provides output signal S_(Output1) to LED sub-array 120. Further, input 111 provides input signal S_(Input2) to LED driver circuit 141 and, in response, LED driver circuit 141 provides output signal S_(Output2) to LED sub-array 121. Input 112 provides an input signal S_(Input3) to LED driver circuit 141 and, in response, LED driver circuit 141 provides an output signal S_(Output3) to LED sub-array 122. Input 113 provides an input signal S_(Input4) to LED driver circuit 141 and, in response, LED driver circuit 141 provides an output signal S_(Output4) to LED sub-array 123. Input 114 provides an input signal S_(Input5) to LED driver circuit 141 and, in response, LED driver circuit 141 provides an output signal S_(Output5) to LED sub-array 124. In this way, inputs 110-114 are operatively coupled to LED array 102 through LED sub-controller 131.

In this embodiment, and as shown in FIG. 6 b, LED sub-controller 132 is operatively coupled to inputs 110, 111, 112, 113 and 114, as well as to LED array 103. In this embodiment, LED sub-controller 132 includes LED driver circuits 145, 146, 147, 148 and 149 operatively coupled to LED sub-arrays 125, 126, 127, 128 and 129, respectively. Further, inputs 110, 111, 112, 113 and 114 are operatively coupled with LED driver circuits 145, 146, 147, 148 and 149, respectively.

In operation, input 110 provides input signal S_(Input1) to LED driver circuit 145 and, in response, LED driver circuit 145 provides output signal S_(Output1) to LED sub-array 125. Further, input 111 provides input signal S_(Input2) to LED driver circuit 146 and, in response, LED driver circuit 146 provides output signal S_(Output2) to LED sub-array 126. Input 112 provides input signal S_(Input3) to LED driver circuit 147 and, in response, LED driver circuit 147 provides output signal S_(Output3) to LED sub-array 127. Input 113 provides input signal S_(Input4) to LED driver circuit 148 and, in response, LED driver circuit 148 provides output signal S_(Output4) to LED sub-array 128. Input 114 provides input signal S_(Input3) to LED driver circuit 149 and, in response, LED driver circuit 149 provides output signal S_(Output5) to LED sub-array 129. In this way, inputs 110-114 are operatively coupled to LED array 103 through LED sub-controller 132.

In some embodiments, inputs 110-114 each operate as a switch which is repeatably movable between active and deactive conditions, as described in more detail above with FIGS. 1 a, 1 b and 1 c. However, in this embodiment, inputs 110-114 include potentiometers, as will be discussed in more detail below.

FIG. 7 a is a schematic diagram of input 110 operatively coupled to LED sub-array 120 through LED driver circuit 140, wherein input 110 operates as a potentiometer. In this embodiment, input 110 includes potentiometer 137 a, which is connected between power terminal 108 a and current return 136. The output of potentiometer 137 a is connected to LED driver circuit 140, which includes LED driver circuit chip 150, so that LED driver circuit 140 receives input signal S_(Input1). LED driver circuit chip 150 provides output signal S_(Output1) to LED sub-array 120 (FIG. 6 a) in response to receiving input signal S_(Input1) from input 110. In particular, LED driver circuit chip 150 provides output signal S_(Output1) to LEDs 120 a-120 e. LEDs 120 a-120 e emit UV light 160 in response to being activated by output signal S_(Output1). Further, LEDs 120 a-120 e do not emit UV light 160 in response to being deactivated by output signal S_(Output1).

It should be noted that more information regarding LED driver circuits and LED driver circuit chips, as well as the connections of the components of lighting system 100 a, is provided in more detail above with the discussion of FIGS. 1 a, 1 b and 1 c, as well as with the discussion of FIGS. 2 a and 2 b.

FIG. 7 b is a schematic diagram of input 111 operatively coupled to LED sub-array 121 through LED driver circuit 141, wherein input 111 operates as a potentiometer. In this embodiment, input 111 includes potentiometer 137 b, which is connected between power terminal 108 a and current return 136. The output of potentiometer 137 b is connected to LED driver circuit 141, which includes LED driver circuit chip 151, so that LED driver circuit 141 receives input signal S_(Input2). LED driver circuit chip 151 provides output signal S_(Output2) to LED sub-array 121 (FIG. 6 a) in response to receiving input signal S_(Input2) from input 111. In particular, LED driver circuit chip 151 provides output signal S_(Output2) to LEDs 121 a-121 e. LEDs 121 a-121 e emit blue light 162 in response to being activated by output signal S_(Output2). Further, LEDs 121 a-121 e do not emit blue light 162 in response to being deactivated by output signal S_(Output2).

FIG. 7 c is a schematic diagram of input 112 operatively coupled to LED sub-array 122 through LED driver circuit 142, wherein input 112 operates as a potentiometer. In this embodiment, input 112 includes a potentiometer 137 c, which is connected between power terminal 108 a and current return 136. The output of potentiometer 137 c is connected to LED driver circuit 142, which includes an LED driver circuit chip 152, so that LED driver circuit 142 receives input signal S_(Input3). LED driver circuit chip 152 provides output signal S_(Output3) to LED sub-array 122 (FIG. 6 a) in response to receiving input signal S_(Input3) from input 112. In particular, LED driver circuit chip 152 provides output signal S_(Output3) to LEDs 122 a-122 e. LEDs 122 a-122 e emit green light 163 in response to being activated by output signal S_(Output3). Further, LEDs 122 a-122 e do not emit green light 163 in response to being deactivated by output signal S_(Output3).

FIG. 7 d is a schematic diagram of input 113 operatively coupled to LED sub-array 123 through LED driver circuit 143, wherein input 113 operates as a potentiometer. In this embodiment, input 113 includes a potentiometer 137 d, which is connected between power terminal 108 a and current return 136. The output of potentiometer 137 d is connected to LED driver circuit 143, which includes an LED driver circuit chip 153, so that LED driver circuit 143 receives input signal S_(Input4). LED driver circuit chip 153 provides output signal S_(Output4) to LED sub-array 123 (FIG. 6 a) in response to receiving input signal S_(Input4) from input 113. In particular, LED driver circuit chip 153 provides output signal S_(Output4) to LEDs 123 a-123 e. LEDs 123 a-123 e emit red light 166 in response to being activated by output signal S_(Output4) Further, LEDs 123 a-123 e do not emit red light 166 in response to being deactivated by output signal S_(Output4).

FIG. 7 e is a schematic diagram of input 114 operatively coupled to LED sub-array 124 through LED driver circuit 144, wherein input 114 operates as a potentiometer. In this embodiment, input 114 includes a potentiometer 137 e, which is connected between power terminal 108 a and current return 136. The output of potentiometer 137 e is connected to LED driver circuit 144, which includes an LED driver circuit chip 154, so that LED driver circuit 144 receives input signal S_(Input5). LED driver circuit chip 154 provides output signal S_(Output5) to LED sub-array 124 (FIG. 6 a) in response to receiving input signal S_(Input5) from input 114. In particular, LED driver circuit chip 154 provides output signal S_(Output5) to LEDs 124 a-124 e. LEDs 124 a-124 e emit IR light 167 in response to being activated by output signal S_(Output5). Further, LEDs 124 a-124 e do not emit IR light 167 in response to being deactivated by output signal S_(Output5).

FIG. 8 a is a schematic diagram of input 110 operatively coupled to LED sub-array 125 through LED driver circuit 145. As mentioned above, input 110 includes potentiometer 137 a, which is connected between power terminal 108 a and current return 136. In this embodiment, the output of potentiometer 137 a is connected to LED driver circuit 145, which includes an LED driver circuit chip 155, so that LED driver circuit 145 receives input signal S_(Input1). LED driver circuit chip 155 provides output signal S_(Output1) to LED sub-array 125 (FIG. 6 b) in response to receiving input signal S_(Input1) from input 110. In particular, LED driver circuit chip 155 provides output signal S_(Output1) to LEDs 125 a-125 e. LEDs 125 a-125 e emit UV light 160 in response to being activated by output signal S_(Output1). Further, LEDs 125 a-125 e do not emit UV light 160 in response to being deactivated by output signal S_(Output1).

FIG. 8 b is a schematic diagram of input 111 operatively coupled to LED sub-array 126 through LED driver circuit 146. As mentioned above, input 111 includes potentiometer 137 b, which is connected between power terminal 108 a and current return 136. In this embodiment, the output of potentiometer 137 b is connected to LED driver circuit 146, which includes an LED driver circuit chip 156, so that LED driver circuit 146 receives input signal S_(Input2). LED driver circuit chip 156 provides output signal S_(Output2) to LED sub-array 126 (FIG. 6 b) in response to receiving input signal S_(Input2) from input 111. In particular, LED driver circuit chip 156 provides output signal S_(Output2) to LEDs 126 a-126 e. LEDs 126 a-126 e emit blue light 162 in response to being activated by output signal S_(Output2). Further, LEDs 126 a-126 e do not emit blue light 162 in response to being deactivated by output signal S_(Output2)

FIG. 8 c is a schematic diagram of input 112 operatively coupled to LED sub-array 127 through LED driver circuit 147. As mentioned above, input 112 includes potentiometer 137 c, which is connected between power terminal 108 a and current return 136. In this embodiment, the output of potentiometer 137 c is connected to LED driver circuit 147, which includes an LED driver circuit chip 157, so that LED driver circuit 147 receives input signal S_(Input3). LED driver circuit chip 157 provides output signal S_(Output3) to LED sub-array 127 (FIG. 6 b) in response to receiving input signal S_(Input3) from input 112. In particular, LED driver circuit chip 157 provides output signal S_(Output3) to LEDs 127 a-127 e. LEDs 127 a-1272 e emit green light 163 in response to being activated by output signal S_(Output3). Further, LEDs 127 a-127 e do not emit green light 163 in response to being deactivated by output signal S_(Output3).

FIG. 8 d is a schematic diagram of input 113 operatively coupled to LED sub-array 128 through LED driver circuit 148. As mentioned above, input 113 includes potentiometer 137 d, which is connected between power terminal 108 a and current return 136. In this embodiment, the output of potentiometer 137 d is connected to LED driver circuit 148, which includes an LED driver circuit chip 158, so that LED driver circuit 148 receives input signal S_(Input4). LED driver circuit chip 158 provides output signal S_(Output4) to LED sub-array 128 (FIG. 6 b) in response to receiving input signal S_(Input4) from input 113. In particular, LED driver circuit chip 158 provides output signal S_(Output4) to LEDs 127 a-127 e. LEDs 127 a-127 e emit red light 166 in response to being activated by output signal S_(Output4). Further, LEDs 127 a-127 e do not emit red light 166 in response to being deactivated by output signal S_(Output4).

FIG. 8 e is a schematic diagram of input 114 operatively coupled to LED sub-array 129 through LED driver circuit 149. As mentioned above, input 114 includes potentiometer 137 e, which is connected between power terminal 108 a and current return 136. In this embodiment, the output of potentiometer 137 e is connected to LED driver circuit 149, which includes an LED driver circuit chip 159, so that LED driver circuit 149 receives input signal S_(Input5). LED driver circuit chip 159 provides output signal S_(Output5) to LED sub-array 129 (FIG. 6 b) in response to receiving input signal S_(Input5) from input 114. In particular, LED driver circuit chip 159 provides output signal S_(Output5) to LEDs 129 a-129 e. LEDs 129 a-129 e emit IR light 167 in response to being activated by output signal S_(Output5). Further, LEDs 129 a-129 e do not emit IR light 167 in response to being deactivated by output signal S_(Output5).

As mentioned above, the light emitting diodes included with LED arrays 102 and 103 can emit many different colors of light in response to output signals received from LED controller 130, as will be discussed in more detail presently.

FIG. 9 a is a graph of a wavelength spectrum 192 of light provided by lighting system 100 b, wherein wavelength spectrum 192 includes color mixing. In FIG. 9 a, wavelength spectrum 192 corresponds to the intensity of light versus wavelength (nm), as discussed above with wavelength spectrum 180.

As mentioned above with FIGS. 7 a and 8 a, input 110 includes potentiometer 137 a. In some situations, potentiometer 137 a is adjusted so the power of input signal S_(Input1) and output signal S_(Output1) are decreased. The intensity of UV light 160 decreases, as indicated by wavelength spectrum 192 b, in response to decreasing the power of input signal S_(Input1) and output signal S_(Output1) with potentiometer 137 a.

In some situations, potentiometer 137 a is adjusted so the power of input signal S_(Input1) and output signal S_(Output1) are increased. The intensity of UV light 160 increases, as indicated by wavelength spectrum 192 c, in response to increasing the power of input signal S_(Input1) and output signal S_(Output1) with potentiometer 137 a.

As mentioned above with FIGS. 7 b and 8 b, input 111 includes potentiometer 137 b. In some situations, potentiometer 137 b is adjusted so the power of input signal S_(Input2) and output signal S_(Output2) are decreased. The intensity of blue light 162 decreases, as indicated by wavelength spectrum 193 b, in response to decreasing the power of input signal S_(Input2) and output signal S_(Output2) with potentiometer 137 b.

In some situations, potentiometer 137 b is adjusted so the power of input signal S_(Input2) and output signal S_(Output2) are increased. The intensity of blue light 162 increases, as indicated by wavelength spectrum 193 c, in response to increasing the power of input signal S_(Input2) and output signal S_(Output2) with potentiometer 137 b.

As mentioned above with FIGS. 7 c and 8 c, input 112 includes potentiometer 137 c. In some situations, potentiometer 137 c is adjusted so the power of input signal S_(Input3) and output signal S_(Output3) are decreased. The intensity of green light 163 decreases, as indicated by wavelength spectrum 194 b, in response to decreasing the power of input signal S_(Input3) and output signal S_(Output3) with potentiometer 137 c.

In some situations, potentiometer 137 c is adjusted so the power of input signal S_(Input3) and output signal S_(Output3) are increased. The intensity of green light 163 increases, as indicated by wavelength spectrum 194 c, in response to increasing the power of input signal S_(Input3) and output signal S_(Output3) with potentiometer 137 c.

As mentioned above with FIGS. 7 d and 8 d, input 113 includes potentiometer 137 d. In some situations, potentiometer 137 d is adjusted so the power of input signal S_(Input4) and output signal S_(Output4) are decreased. The intensity of red light 166 decreases, as indicated by wavelength spectrum 195 b, in response to decreasing the power of input signal S_(Input4) and output signal S_(Output4) with potentiometer 137 d.

In some situations, potentiometer 137 d is adjusted so the power of input signal S_(Input4) and output signal S_(Output4) are increased. The intensity of red light 166 increases, as indicated by wavelength spectrum 195 d, in response to increasing the power of input signal S_(Input4) and output signal S_(Output4) with potentiometer 137 d.

As mentioned above with FIGS. 7 e and 8 e, input 114 includes potentiometer 137 e. In some situations, potentiometer 137 e is adjusted so the power of input signal S_(Input5) and output signal S_(Output5) are decreased. The intensity of IR light 167 decreases, as indicated by wavelength spectrum 196 b, in response to decreasing the power of input signal S_(Input5) and output signal S_(Output5) with potentiometer 137 e.

In some situations, potentiometer 137 e is adjusted so the power of input signal S_(Input5) and output signal S_(Output5) are increased. The intensity of IR light 167 increases, as indicated by wavelength spectrum 195 e, in response to increasing the power of input signal S_(Input5) and output signal S_(Output5) with potentiometer 137 e. In this way, the light emitting diodes included with LED arrays 102 and 103 emit different colors of light in response to output signals received from LED controller 130.

FIG. 9 b is a graph of a wavelength spectrum 200 of light provided by lighting system 100 b, wherein wavelength spectrum 200 includes color mixing. In FIG. 9 b, wavelength spectrum 200 corresponds to the intensity of light versus wavelength (nm), as discussed above with wavelength spectrum 180.

In this example, potentiometer 137 a is adjusted so the power of input signal S_(Input1) and output signal S_(Output1) are adjusted, and the intensity of UV light 160 is driven to zero. In this example, potentiometer 137 b is adjusted so the power of input signal S_(Input2) and output signal S_(Output2) are adjusted, and the intensity of blue light 162 is driven to that indicated by wavelength spectrum 193 a. In this example, potentiometer 137 c is adjusted so the power of input signal S_(Input3) and output signal S_(Output3) are adjusted, and the intensity of green light 163 is driven to that indicated by wavelength spectrum 194 b.

In this example, potentiometer 137 d is adjusted so the power of input signal S_(Input4) and output signal S_(Output4) are adjusted, and the intensity of red light 166 is driven to that indicated by wavelength spectrum 195 a. In this example, potentiometer 137 e is adjusted so the power of input signal S_(Input5) and output signal S_(Output5) are adjusted, and the intensity of IR light 167 is driven to that indicated by wavelength spectrum 196 c.

FIG. 9 c is a graph of a wavelength spectrum 201 of light provided by lighting system 100 b, wherein wavelength spectrum 201 includes color mixing. In FIG. 9 c, wavelength spectrum 201 corresponds to the intensity of light versus wavelength (nm), as discussed above with wavelength spectrum 180.

In this example, potentiometer 137 a is adjusted so the power of input signal S_(Input1) and output signal S_(Output1) are adjusted, and the intensity of UV light 160 is driven to zero. In this example, potentiometer 137 b is adjusted so the power of input signal S_(Input2) and output signal S_(Output2) are adjusted, and the intensity of blue light 162 is driven to that indicated by wavelength spectrum 193 a. In this example, potentiometer 137 c is adjusted so the power of input signal S_(Input3) and output signal S_(Output3) are adjusted, and the intensity of green light 163 is driven to that indicated by wavelength spectrum 194 c.

In this example, potentiometer 137 d is adjusted so the power of input signal S_(Input4) and output signal S_(Output4) are adjusted, and the intensity of red light 166 is driven to that indicated by wavelength spectrum 195 b. In this example, potentiometer 137 e is adjusted so the power of input signal S_(Input5) and output signal S_(Output5) are adjusted, and the intensity of IR light 167 is driven to that indicated by wavelength spectrum 196 b.

It should be noted that the desired mixture of light provided by lighting system 100 b can be chosen to correspond to an action spectrum of a physiological activity of a plant, as will be discussed in more detail presently.

FIG. 9 d is a graph of a wavelength spectrum 202 of light provided by lighting system 100 b, wherein wavelength spectrum 202 includes color mixing. Action spectrum corresponding to chlorophyll a is also shown in FIG. 9 d. In FIG. 9 d, wavelength spectrum 202 and the action spectrum corresponding to chlorophyll a correspond to the intensity of light versus wavelength (nm).

In this example, potentiometer 137 a is adjusted so the power of input signal S_(Input1) and output signal S_(Output1) are adjusted, and the intensity of UV light 160 is driven to zero. In this example, potentiometer 137 b is adjusted so the power of input signal S_(Input2) and output signal S_(Output2) are adjusted, and the intensity of blue light 162 is driven to that indicated by wavelength spectrum 193 a. In this example, potentiometer 137 c is adjusted so the power of input signal S_(Input3) and output signal S_(Output3) are adjusted, and the intensity of green light 163 is driven to zero.

In this example, potentiometer 137 d is adjusted so the power of input signal S_(Input4) and output signal S_(Output4) are adjusted, and the intensity of red light 166 is driven to that indicated by wavelength spectrum 195 a. In this example, potentiometer 137 e is adjusted so the power of input signal S_(Input5) and output signal S_(Output5) are adjusted, and the intensity of IR light 167 is driven to zero. In this way, the desired mixture of light provided by lighting system 100 b is chosen to correspond to the action spectrum corresponding to chlorophyll a.

FIG. 9 e is a graph of a wavelength spectrum 203 of light provided by lighting system 100 b, wherein wavelength spectrum 203 includes color mixing. Action spectrum corresponding to α-carotene is also shown in FIG. 9 e. In FIG. 9 e, wavelength spectrum 203 and the action spectrum corresponding to α-carotene correspond to the intensity of light versus wavelength (nm).

It should be noted that, in this example, LED sub-arrays 120 and 125 include LEDs which emit violet light 161 when activated, and do not emit violet light 161 when deactivated. Hence, LEDs 120 a, 120 b, 120 c, 120 d and 120 e in FIG. 7 a emit violet light 161 instead of UV light 160. Further, LEDs 125 a, 125 b, 125 c, 125 d and 125 e in FIG. 8 a emit blue light 162 instead of UV light 160.

In this example, potentiometer 137 a is adjusted so the power of input signal S_(Input1) and output signal S_(Output1) are adjusted, and the intensity of violet light 161 is driven to that indicated by wavelength spectrum 196 a. In this example, potentiometer 137 b is adjusted so the power of input signal S_(Input2) and output signal S_(Output2) are adjusted, and the intensity of blue light 162 is driven to that indicated by wavelength spectrum 193 a. In this example, potentiometer 137 c is adjusted so the power of input signal S_(Input3) and output signal S_(Output3) are adjusted, and the intensity of green light 163 is driven to zero.

In this example, potentiometer 137 d is adjusted so the power of input signal S_(Input4) and output signal S_(Output4) are adjusted, and the intensity of red light 166 is driven to zero. In this example, potentiometer 137 e is adjusted so the power of input signal S_(Input5) and output signal S_(Output5) are adjusted, and the intensity of IR light 167 is driven to zero. In this way, the desired mixture of light provided by lighting system 100 b is chosen to correspond to the action spectrum corresponding to α-carotene.

FIG. 9 f is a graph of a wavelength spectrum 204 of light provided by lighting system 100 b, wherein wavelength spectrum 204 includes color mixing. Action spectrum corresponding to pelargonin is also shown in FIG. 9 f. In FIG. 9 f, wavelength spectrum 204 and the action spectrum corresponding to pelargonin correspond to the intensity of light versus wavelength (nm).

It should be noted that, in this example, LED sub-arrays 120 and 125 include LEDs which emit green light 163 when activated, and do not emit green light 163 when deactivated. Hence, LEDs 120 a, 120 b, 120 c, 120 d and 120 e in FIG. 7 a emit violet light 161 instead of UV light 160. Further, LEDs 125 a, 125 b, 125 c, 125 d and 125 e in FIG. 8 a emit green light 163 instead of UV light 160.

Further, in this example, LED sub-arrays 121 and 126 include LEDs which emit blue-green light 171 when activated, and do not emit blue-green light 171 when deactivated. Hence, LEDs 121 a, 121 b, 121 c, 121 d and 121 e in FIG. 7 b emit blue-green light 171 instead of blue light 162. Further, LEDs 126 a, 126 b, 126 c, 126 d and 126 e in FIG. 8 b emit blue-green light 171 instead of blue light 162.

In this example, potentiometer 137 a is adjusted so the power of input signal S_(Input1) and output signal S_(Output1) are adjusted, and the intensity of violet light 161 is driven to zero. In this example, potentiometer 137 b is adjusted so the power of input signal S_(Input2) and output signal S_(Output2) are adjusted, and the intensity of blue-green light 171 is driven to that indicated by wavelength spectrum 197 a. In this example, potentiometer 137 c is adjusted so the power of input signal S_(Input3) and output signal S_(Output3) are adjusted, and the intensity of green light 163 is driven to that indicated by wavelength spectrum 194 c.

In this example, potentiometer 137 d is adjusted so the power of input signal S_(Input4) and output signal S_(Output4) are adjusted, and the intensity of red light 166 is driven to zero. In this example, potentiometer 137 e is adjusted so the power of input signal S_(Input5) and output signal S_(Output5) are adjusted, and the intensity of IR light 167 is driven to zero. In this way, the desired mixture of light provided by lighting system 100 b is chosen to correspond to the action spectrum corresponding to pelargonin.

It should be noted that the desired mixture of light provided by lighting system 100 b can be chosen to correspond to a wavelength spectrum of sunlight, as will be discussed in more detail presently.

FIG. 9 g is a graph of a wavelength spectrum 205 of light provided by lighting system 100 b, wherein wavelength spectrum 205 includes color mixing. A wavelength spectrum 197 corresponding to sunlight is also shown in FIG. 9 g. In FIG. 9 g, wavelength spectra 197 and 205 correspond to the intensity of light versus wavelength (nm).

It should be noted that, in this example, LED sub-arrays 120 and 125 include LEDs which emit UV light 160 when activated, and do not emit UV light 160 when deactivated. Hence, LEDs 120 a, 120 b, 120 c, 120 d and 120 e in FIG. 7 a emit UV light 160. Further, LEDs 125 a, 125 b, 125 c, 125 d and 125 e in FIG. 8 a emit violet light 161.

Further, in this example, LED sub-arrays 121 and 126 include LEDs which emit white light 168 when activated, and do not emit white light 168 when deactivated. Hence, LEDs 121 a, 121 b, 121 c, 121 d and 121 e in FIG. 7 b emit white light 168. Further, LEDs 125 a, 125 b, 125 c, 125 d and 125 e in FIG. 8 b emit white light 168. A wavelength spectrum 197 corresponding to white light 168 is also shown in FIG. 9 d. The LEDs of LED sub-arrays 121 and 126 can emit white light 168 in many different ways. In this example, the LEDs of LED sub-arrays 121 and 126 emit white light 168 because they include phosphor coated LEDs, which emit blue light. In another example, the LEDs of LED sub-arrays 121 and 126 emit white light 168 because they include phosphor coated LEDs, which emit UV light.

In this example, potentiometer 137 a is adjusted so the power of input signal S_(Input1) and output signal S_(Output1) are adjusted, and the intensity of UV light 160 is driven to zero. In this example, potentiometer 137 b is adjusted so the power of input signal S_(Input2) and output signal S_(Output2) are adjusted, and the intensity of white light 168 is driven to that indicated by wavelength spectrum 197. In this example, potentiometer 137 c is adjusted so the power of input signal S_(Input3) and output signal S_(Output3) are adjusted, and the intensity of green light 163 is driven to that indicated by wavelength spectrum 194 b.

In this example, potentiometer 137 d is adjusted so the power of input signal S_(Input4) and output signal S_(Output4) are adjusted, and the intensity of red light 166 is driven to that indicated by wavelength spectrum 195 b. In this example, potentiometer 137 e is adjusted so the power of input signal S_(Input5) and output signal S_(Output5) are adjusted, and the intensity of IR light 167 is driven to that indicated by wavelength spectrum 196 b. In this way, the desired mixture of light provided by lighting system 100 b is chosen to correspond to a wavelength spectrum of sunlight.

FIG. 10 is a block diagram of a lighting system 100 c, which includes a programmable logic controller 133 operatively coupled to LED array 102 through LED controller 130. Lighting system 100 c includes a timer circuit 134 operatively coupled to programmable logic circuit 133. timer circuit 134 can be of many different types, such as a 555 timer. 555 timers are made by many different manufacturers. For example, ECG Philips makes the ECG955M chip, Maxim makes the ICM7555 chip and Motorola makes the MC1455/MC1555 chip.

Timer circuit 134 provides a timing signal S_(Timer) to programmable logic circuit 133 and, in response, programmable logic circuit 133 provides input signals S_(Input1), S_(Input2), S_(Input3), S_(Input4) and S_(Input5) to LED controller 130. As discussed in more detail above with FIGS. 6 a and 6 b, as well as with FIGS. 7 a-7 e and FIGS. 8 a-8 e, LED controller 130 provides input signals S_(Output1), S_(Output2), S_(Output3), S_(Output4) and S_(Output5) to LED array 102 in response to receiving input signals S_(Input1), S_(Input2), S_(Input3), S_(Input4) and S_(Input5).

In this embodiment, programmable logic controller 133 is programmed to adjust input signals S_(Input1), S_(Input2), S_(Input3), S_(Input4) and S_(Input5) in response to receiving timing signal S_(Timer). Programmable logic controller 133 can adjust input signals S_(Input1), S_(Input2), S_(Input3), S_(Input4) and S_(Input5) in response to receiving timing signal S_(Timer) in many different ways.

In one example, programmable logic controller 133 adjusts input signals S_(Input1), S_(Input2), S_(Input3), S_(Input4) and S_(Input5) in response to receiving timing signal S_(Timer) so that the relative intensities of light 160, 162, 163, 166 and 167 of FIG. 9 a are adjusted relative to each other, as described in more detail with FIGS. 9 a-9 g. In this way, lighting system 100 c includes a programmable logic circuit which adjusts input signals in response to receiving a timing signal from a timer.

In general, lighting system 100 c allows the intensities of light 160, 162, 163, 166 and 167 to be adjusted relative to each other as a period of time. The period of time can have many different values. For example, in some embodiments, the period of time is in a range from about half an hour to more than one hour. In other embodiments, the period of time is in a range from about a day to several days. The period of time can also be in a range from a day to a week or more, or from a day to a month or more. In one particular embodiment, the period of time corresponds with the yearly cycle of the sun so that lighting system 100 c mimics the sun.

The embodiments of the invention described herein are exemplary and numerous modifications, variations and rearrangements can be readily envisioned to achieve substantially equivalent results, all of which are intended to be embraced within the spirit and scope of the invention as defined in the appended claims. 

1. A lighting system, comprising: an LED array which includes first and second LED sub-arrays; a first input operatively coupled to the first LED sub-array through a controller; and a second input operatively coupled to the second LED sub-array through the controller; wherein the first LED sub-array includes a first light emitting diode which emits a first color of light; a second light emitting diode which emits a second color of light; and a third light emitting diode which emits a third color of light; wherein the intensities of the first and second colors of light are adjustable relative to each other, in response to adjusting an input signal provided to the first input, to drive a wavelength spectrum of light provided by the first LED sub-array to match the action spectrum of the physiological activity of a plant.
 2. The system of claim 1, wherein the first color of light consists essentially of red light.
 3. The system of claim 1, wherein the second color of light consists essentially of blue light.
 4. The system of claim 1, wherein the first, second and third colors of light are different from each other.
 5. The system of claim 1, wherein the first color of light consists essentially of light having a wavelength between about 620 nanometers to about 670 nanometers.
 6. The system of claim 1, wherein the second color of light consists essentially of light having a wavelength between about 400 nanometers to about 500 nanometers.
 7. The system of claim 1, wherein the intensity of the first color of light is about ten to about fifteen times greater than the intensity of the second color of light.
 8. A lighting system, comprising: an LED array which includes a plurality of LED sub-arrays; and a plurality of inputs operatively coupled to a corresponding LED sub-array through a controller; wherein a first LED sub-array of the plurality of LED sub-arrays includes a first light emitting diode which emits red light; and a second light emitting diode which emits blue light; wherein the intensities of the red and blue light are adjustable relative to each other, in response to adjusting an input signal provide to the first LED sub-array, to drive a wavelength spectrum of light provided by the LED array to match the wavelength spectrum of sunlight.
 9. The system of claim 8, wherein the red color of light consists essentially of light having a wavelength between about 620 nanometers to about 670 nanometers.
 10. The system of claim 8, wherein the blue color of light consists essentially of light having a wavelength between about 400 nanometers to about 500 nanometers.
 11. The system of claim 8, further including a third light emitting diode which emits light having a wavelength different from the light emitted by the first and second light emitting diodes.
 12. The system of claim 8, further including a third light emitting diode which emits light consisting essentially of light having a wavelength between about 40 nanometers to about 380 nanometers.
 13. The system of claim 8, further including a third light emitting diode which emits light consisting essentially of light having a wavelength between about 750 nanometers to about 2500 nanometers.
 14. The system of claim 8, further including a third light emitting diode which emits light consisting essentially of light having a wavelength between about 660 nanometers to about 700 nanometers.
 15. A lighting system, comprising: an LED array which includes a plurality of LED sub-arrays; and a plurality of inputs operatively coupled to a corresponding LED sub-array through a controller; wherein the intensity of light emitted by the LED sub-arrays is adjustable in response to adjusting input signals provided by the inputs; wherein the intensity of light emitted by the LED sub-arrays is adjustable, in response to adjusting the input signals, to drive a first wavelength spectrum of the LED array to match the action spectrum of the physiological activity of a plant.
 16. The system of claim 15, wherein the intensity of light emitted by the LED sub-arrays is adjustable relative to each other in response to adjusting the input signals.
 17. The system of claim 15, wherein the intensity of light emitted by first and second LED sub-arrays of the plurality of LED sub-arrays is adjustable, in response to adjusting the input signals, to drive the first wavelength spectrum of the LED array to match the action spectrum of the physiological activity of the plant.
 18. The system of claim 15, wherein the intensity of light emitted by a second LED sub-array of the plurality of LED sub-arrays is adjustable, in response to adjusting the input signals, to drive a second wavelength spectrum of the LED array to match the action spectrum of the physiological activity of a plant pigment of the plant.
 19. The system of claim 15, wherein the intensity of light emitted by a third LED sub-array of the plurality of LED sub-arrays is adjustable, in response to adjusting the input signals, to drive a third wavelength spectrum of the LED array to match the wavelength spectrum of sunlight.
 20. The system of claim 15, further including a programmable logic circuit operatively coupled to the inputs, and a timer operatively coupled to the programmable logic circuit.
 21. The system of claim 20, wherein the programmable logic circuit adjusts the input signals in response to receiving a timing signal from the timer.
 22. A lighting system, comprising: an LED array which includes first and second LED sub-arrays; a first input operatively coupled to the first LED sub-array through a controller; and a second input operatively coupled to the second LED sub-array through the controller; wherein the intensity of light emitted by the first and second LED sub-arrays is adjustable in response to adjusting input signals of the first and second inputs; wherein the intensity of light emitted by the LED sub-arrays is adjustable, in response to adjusting the input signals, to drive a wavelength spectrum of the LED array to match the action spectrum of the physiological activity of a plant.
 23. A lighting system, comprising: an LED array which includes first and second LED sub-arrays; a first input operatively coupled to the first LED sub-array through a controller; and a second input operatively coupled to the second LED sub-array through the controller; wherein the intensity of light emitted by the first and second LED sub-arrays is adjustable in response to adjusting input signals of the first and second inputs; wherein the intensity of light emitted by the LED sub-arrays is adjustable, in response to adjusting the input signals, to drive a wavelength spectrum of the LED array to match the action spectrum of the physiological activity of a plant pigment.
 24. A lighting system, comprising: an LED array which includes first and second LED sub-arrays; a first input operatively coupled to the first LED sub-array through a controller; and a second input operatively coupled to the second LED sub-array through the controller; wherein the intensity of light emitted by the first and second LED sub-arrays is adjustable in response to adjusting input signals provided by the first and second inputs; wherein the intensity of light emitted by the LED sub-arrays is adjustable, in response to adjusting the input signals, to drive a wavelength spectrum of the LED array to match the wavelength spectrum of sunlight. 